Hybrid electric vehicle, drive control method and device of the same

ABSTRACT

The present disclosure provides a hybrid electric vehicle, a drive control method and a drive control device of a hybrid electric vehicle. The drive control method includes: obtaining a current gear position and a current operating mode of the hybrid electric vehicle, a current electric charge level of a power battery and a slope of a road on which the hybrid electric vehicle is driving; determining whether the hybrid electric vehicle is within a taxiing start-stop interval according to the current gear position of the hybrid electric vehicle, the current electric charge level of the power battery, and the slope of the road; if the hybrid electric vehicle is within the taxiing start-stop interval, obtaining a current speed of the hybrid electric vehicle; and causing the hybrid electric vehicle to enter a small load stop mode or a small load stall mode according to the current speed.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to, and benefits of Chinese PatentApplication No. 201510134343.1, filed with the State IntellectualProperty Office of China, on Mar. 25, 2015, the entire content of whichapplication is incorporated herein by reference.

The present application is related to U.S. patent application Ser. No.______ entitled “HYBRID ELECTRIC VEHICLE, DRIVE CONTROL METHOD ANDDEVICE OF THE SAME” filed Mar. 23, 2016 (Attorney Docket No.100758-5067-US), U.S. patent application Ser. No. ______ entitled“HYBRID ELECTRIC VEHICLE, DRIVE CONTROL METHOD AND DEVICE OF THE SAME”filed Mar. 23, 2016 (Attorney Docket No. 100758-5068-US), U.S. patentapplication Ser. No. ______ entitled “HYBRID ELECTRIC VEHICLE, DRIVECONTROL METHOD AND DEVICE OF THE SAME” filed Mar. 23, 2016 (AttorneyDocket No. 100758-5069-US), U.S. patent application Ser. No. ______entitled “HYBRID ELECTRIC VEHICLE, DRIVE CONTROL METHOD AND DEVICE OFTHE SAME” filed ______ (Attorney Docket No. 100758-5070-US), and U.S.patent application Ser. No. ______ entitled “HYBRID ELECTRIC VEHICLE,DRIVE CONTROL METHOD AND DEVICE OF THE SAME” filed ______ (AttorneyDocket No. 100758-5071-US), all of which are incorporated by referencein their entirety.

TECHNICAL FIELD

The present disclosure relates to vehicle technology field, moreparticularly to a hybrid electric vehicle, a drive control method and adrive control device of the hybrid electric vehicle.

BACKGROUND

A traditional fuel vehicle is usually equipped with an additionalautomatic start-stop subsystem for realizing taxiing start-stop controlon the vehicle, and thus fuel waste and air pollution caused by engineidling are reduced. There have been following forms of start-stopsystems in vehicles.

1. Separating Starter/Generator Start-Stop System

In such a system, the starter and the generator are designed separately,in which the starter is used to provide power for starting an engine,and the generator is used to provide electric energy for the starter.This system includes a high enhanced starter, an enhanced battery(usually an AGM battery), a controllable generator, an engine ECU(Electronic Control Unit) with integrated start-stop coordinationprogram, and a sensor, etc. In this system, the engine is started by thestarter separately.

2. Integrated Starter/Generator Start-Stop System

The integrated start/generator is a synchronous machine actuated by asingle teeth stator and a rotor in a permanent magnet, and a drivingunit may be integrated into a hybrid power transmission system. Withthis system, the engine may be started by revise driving from the motor.

3. i-Start System

An electric control device is integrated in the generator. The enginestops when the vehicle stops at a red light, and automatically starts assoon as engaging a gear or releasing a brake pedal.

When the vehicle is driven on heavy-traffic roads, the engine will bestarted frequently, that is a huge test for both a spark plug and abattery. Although the start-stop systems described-above are intelligentenough, a service life of the engine will be shorten as an abrasion onthe engine, and a vibration and a noise are inevitable as frequentstart-stop, which severely reduces the comfort. In addition, theautomatic start-stop system may work only in such conditions that avehicle speed is 0, a rotating speed of the engine is lower than aprescribed target speed, the refrigerant is in a required range, thevacuum braking meets a required condition, an air conditioner isadjusted suitably, the braking pedal is depressed at a certain gearposition (like N or P), and an electric charge level of the powerbattery meets a next start. Since the start-stop system is limited onmany aspects, system units are required to have a high reliability anddurability. Moreover, the special start-stop system increases the costof the vehicle.

SUMMARY

Embodiments of the present disclosure seek to solve at least one of theproblems existing in the related art to at least some extent.

For this, according to embodiments of a first aspect of the presentdisclosure, a drive control method of a hybrid electric vehicle isprovided. The method includes: obtaining a current gear position of thehybrid electric vehicle, a current electric charge level of a powerbattery and a slope of a road on which the hybrid electric vehicle isdriving; determining whether the hybrid electric vehicle is within ataxiing start-stop interval according to the current gear position ofthe hybrid vehicle, the current electric charge level of the powerbattery, and the slope of the road; if the hybrid electric vehicle iswithin the taxiing start-stop interval, further obtaining a currentspeed of the hybrid electric vehicle; and causing the hybrid electricvehicle to enter a small load stop mode or a small load stall modeaccording to the current speed.

With the drive control method of the hybrid electric vehicle accordingto embodiments of the present disclosure, whether the hybrid electricvehicle is within the taxiing start-stop interval is determinedaccording to information such as the current gear position of the hybridelectric vehicle and the current electric charge level of the powerbattery, and if the hybrid electric vehicle is within the taxiingstart-stop interval, the hybrid electric vehicle is configured to entera small load stop mode or a small load stall mode according to thecurrent speed. In this way, a driving distance for the vehicle may beincreased, an economy performance may be improved, and fuel consumptionand emission may be reduced, without increasing a working frequency ofthe starter, thus ensuring a working life of components. In addition, ifthe vehicle has an accelerator-releasing energy feedback function,wasted kinetic energy may be converted to electric energy by a motorthrough the energy feedback and stored in a power battery, thusincreasing energy recovery. Moreover, for the hybrid electric vehicles,problems of bad ride comfort and bad power performance caused byfrequent start-stop of the engine may be solved effectively.

According to embodiments of a second aspect of the present disclosure, adrive control device of a hybrid electric vehicle is provided. Thedevice includes: a first obtaining module, configured to obtain acurrent gear position of the hybrid electric vehicle, a current electriccharge level of a power battery and a slope of a road on which thehybrid electric vehicle is driving; a determining module, configured todetermine whether the hybrid electric vehicle is within a taxiingstart-stop interval according to the current gear position of the hybridvehicle, the current electric charge level of the power battery, and theslope of the road; a second obtaining module, configured to obtain acurrent speed of the hybrid electric vehicle, if the hybrid electricvehicle is within the taxiing start-stop interval; and a first controlmodule, configured to cause the hybrid electric vehicle to enter a smallload stop mode or a small load stall mode according to the currentspeed.

With the drive control device of the hybrid electric vehicle accordingto embodiments of the present disclosure, whether the hybrid electricvehicle is within the taxiing start-stop interval is determinedaccording to information such as the current gear position of the hybridelectric vehicle and the current electric charge level of the powerbattery, and if the hybrid electric vehicle is within the taxiingstart-stop interval, the hybrid electric vehicle is configured to entera small load stop mode or a small load stall mode according to thecurrent speed. In this way, a driving distance for the vehicle may beincreased, an economy performance may be improved, and fuel consumptionand emission may be reduced, without increasing a working frequency ofthe starter, thus ensuring a working life of components. In addition, ifthe vehicle has an accelerator-releasing energy feedback function,wasted kinetic energy may be converted to electric energy by a motorthrough the energy feedback and stored in a power battery, thusincreasing energy recovery. Moreover, for the hybrid electric vehicles,problems of bad ride comfort and bad power performance caused byfrequent start-stop of the engine may be solved effectively.

According to embodiments of a third aspect of the present disclosure, ahybrid electric vehicle is provided. The hybrid electric vehicleincludes the drive control device mentioned in the above embodiments ofthe second aspect of the present disclosure.

With the hybrid electric vehicle according to embodiments of the presentdisclosure, whether the hybrid electric vehicle is within the taxiingstart-stop interval is determined according to information such as thecurrent gear position of the hybrid electric vehicle and the currentelectric charge level of the power battery, and if the hybrid electricvehicle is within the taxiing start-stop interval, the hybrid electricvehicle is configured to enter a small load stop mode or a small loadstall mode according to the current speed. In this way, a drivingdistance for the vehicle may be increased, an economy performance may beimproved, and fuel consumption and emission may be reduced, withoutincreasing a working frequency of the starter, thus ensuring a workinglife of components. In addition, if the vehicle has anaccelerator-releasing energy feedback function, wasted kinetic energymay be converted to electric energy by a motor through the energyfeedback and stored in a power battery, thus increasing energy recovery.Moreover, for the hybrid electric vehicles, problems of bad ride comfortand bad power performance caused by frequent start-stop of the enginemay be solved effectively.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the presentdisclosure will become apparent and more readily appreciated from thefollowing descriptions made with reference to the accompanying drawings,in which:

FIG. 1 is a flow chart of a drive control method of a hybrid electricvehicle according to an embodiment of the present disclosure;

FIG. 2 is a flow chart of determining whether a hybrid electric vehicleis within a taxiing start-stop interval according to an embodiment ofthe present disclosure;

FIG. 3 is a flow chart of controlling a hybrid electric vehicle to entera small load stop mode or a small load stall mode according to anembodiment of the present disclosure;

FIG. 4 is a schematic diagram of energy transfer in a drive controlprocess of a hybrid electric vehicle according to an embodiment of thepresent disclosure;

FIG. 5 is a schematic diagram of control information interaction in adrive control process of a hybrid electric vehicle according to anembodiment of the present disclosure;

FIG. 6 is a flow chart of a drive control method of a hybrid electricvehicle according to an example embodiment of the present disclosure;

FIG. 7 is a block diagram of a drive control device of a hybrid electricvehicle according to an embodiment of the present disclosure;

FIG. 8 is a block diagram of a drive control device of a hybrid electricvehicle according to another example embodiment of the presentdisclosure.

FIG. 9 is a block diagram of a drive control device of a hybrid electricvehicle according to yet another embodiment of the present disclosure.

DETAILED DESCRIPTION

Example embodiments will be described in detail herein, and examplesthereof are illustrated in accompanying drawings. Throughout figuresreferred by the following description, the same reference number indifferent figures indicates the same or similar elements unlessotherwise stated. Implementations described in the following exemplaryembodiments do not represent all the implementations consistent with thepresent disclosure. Instead, they are only examples of the device andmethod consistent with some aspects of the present disclosure detailedin the appended claims.

A drive control method and device of a hybrid electric vehicle accordingto embodiments of the present disclosure will be described withreference to drawings.

FIG. 1 is a flow chart of a drive control method of a hybrid electricvehicle according to an embodiment of the present disclosure. As shownin FIG. 1, the control drive method includes following steps.

In step S101, a current gear position of the hybrid electric vehicle, acurrent electric charge level of a power battery and a slope of a roadon which the hybrid electric vehicle is driving are obtained.

The current gear position may be obtained by a gearbox system of thehybrid electric vehicle through obtaining a gear signal. The currentelectric charge level of the power battery may be obtained by a BMS(Battery Management System) in the hybrid electric vehicle. The slope ofthe road may be computed from a longitudinal acceleration of thevehicle, which is obtained by a longitudinal acceleration sensor in thehybrid electric vehicle.

Specifically, the current gear position of the hybrid electric vehicle,the current electric charge level of the power battery and the slope ofthe road may be obtained via communication between an internalcommunication network of the hybrid electric vehicle, e.g. CAN(Controller Area Network) and the gearbox system, the BMS and thelongitudinal acceleration sensor.

In step S102, it is determined whether the hybrid electric vehicle iswithin a taxiing start-stop interval according to the current gearposition of the hybrid electric vehicle, the current electric chargelevel of the power battery, and the slope of the road on which thehybrid electric vehicle is driving.

In embodiments of the present disclosure, the drive control method maybe performed only when the gear position of the vehicle is atD-position, i.e., when the vehicle is driving.

When the power battery of the hybrid electric vehicle offers electricenergy, a motor can work, and then the vehicle can have the taxiingstart-stop function. Thus, the taxiing start-stop control is performedwhen the electric charge level of the power battery is sufficient.

Since a motor has a limited power output, it is difficult for the motoras an alone driving source to satisfy the power requirement of thevehicle, especially when the vehicle is climbing a sizable slope. Thus,an engine is required to output power when the vehicle is climbing aslope. However, when the vehicle is driving downhill, the drivingresistance may be completely overcome by gravity inertia, and thus therequired torque is small. In this case, the engine may be configured tostop, a clutch may be released totally, and only the motor may be usedto output power. On one hand, the fuel needed during the engine idlingis saved, and on the other hand, if the hybrid electric vehicle has theaccelerator-releasing energy feedback function, an energy feedback bythe motor may be increased, since the clutch is completely released, anda drag force from the engine disappears.

In step S103, a current speed of the hybrid electric vehicle isobtained, if the hybrid electric vehicle is within the taxiingstart-stop interval.

The current speed of the hybrid electric vehicle may be obtained from anESC (Electrical Speed Controller) via the communication network in thehybrid electric vehicle.

In step S104, the hybrid electric vehicle is configured to enter a smallload stop mode or a small load stall mode according to the currentspeed.

FIG. 3 is a flow chart of controlling a hybrid electric vehicle to entera small load stop mode or a small load stall mode according to anembodiment of the present disclosure. As shown in FIG. 3, followingsteps are performed.

In step S301, an engine is configured to stop and a motor is configuredto output power separately, if the current speed is less than a thirdspeed threshold.

In step S302, the hybrid electric vehicle is configured to enter thesmall load stop mode if the current speed is greater than or equal to athird speed threshold, and less than a fourth speed threshold.

Specifically, it may be first determined whether the engine is in anoperating state.

If the engine is not in the operating state, it may be furtherdetermined whether an accelerator push depth is greater than or equal toa first accelerator threshold. If the accelerator push depth is greaterthan the first accelerator threshold, the engine is started; and if theaccelerator push depth is less than the first accelerator threshold, thestate of the engine remains unchanged.

If the engine is in the operating state, it may be further determinedwhether the accelerator push depth is less than a second acceleratorthreshold. If the accelerator push depth is less than the secondaccelerator threshold, the engine is configured to stop; and if theaccelerator push depth is greater than or equal to the secondaccelerator threshold, the state of the engine remains unchanged.

The first accelerator threshold and the second accelerator threshold maybe set according to a driving habit of a user and a performance of thehybrid electric vehicle. The second accelerator threshold is less thanthe first accelerator threshold, thus avoiding a frequent enginestart-stop caused by unclear accelerator thresholds.

In step 303, the hybrid electric vehicle is configured to enter thesmall load stall mode, if the current speed is greater than or equal tothe fourth speed threshold, and less than a fifth speed threshold.

Specifically, it may be first determined whether the engine is in theoperating state.

If the engine is not in the operating state, it may be furtherdetermined whether the accelerator push depth is greater than or equalto the first accelerator threshold. If the accelerator push depth isgreater than the first accelerator threshold, the engine is started; andif the accelerator push depth is less than the first acceleratorthreshold, the state of the engine remains unchanged.

If the engine is in the operating state, it may be further whether theaccelerator push depth is less than the second accelerator threshold. Ifthe accelerator push depth is less than the second acceleratorthreshold, the engine is configured to stall, the clutch is remained inthe coupling state, and fuel supply for the engine is cut off; and ifthe accelerator push depth is greater than or equal to the secondaccelerator threshold, the state of the engine remains unchanged.

In step S304, a state of the engine is remained unchanged if the currentspeed is greater than the fifth speed threshold.

The third, fourth and fifth speed thresholds may be set according to thedriving habit of the user and the power consumption of the vehicle.

In embodiments of the present disclosure, stopping the engine refers toa state in which fuel supply for the engine is cut off and the clutch isreleased, stalling the engine refers to a state in which fuel supply forthe engine is cut off and the clutch is in a coupling state.

In embodiments of the present disclosure, the vehicle has theaccelerator-releasing energy feedback function, and during theaccelerator is released, the lost kinetic energy is converted toelectric energy via the energy feedback of the motor and stored in thepower battery. In this case, if the engine is stopped, the clutch isreleased totally and the drag force from the engine disappears, then theenergy feedback by the motor is increased.

With the drive control method according to embodiments of the presentdisclosure, the hybrid electric vehicle is configured to enter the smallload stall mode (the clutch keeps the coupling state) when the speed ofthe hybrid electric vehicle is relatively higher, since in this case,the vehicle motion inertia is large, and the drag force from the engineis relatively small, and thus has a little impact on the feedbackcharging of the power battery. Furthermore, the clutch keeps thecoupling state, such that it does not require closing the clutch again,thus reducing the friction loss of the clutch. Moreover, when thevehicle speed is lower, the clutch is configured to open so as to avoidinfluence on charging the power battery, since in this case, the vehiclemotion inertia is small, and the drag force from the engine isrelatively large, which has a great impact on the feedback charging ofthe power battery.

After the hybrid electric vehicle enters the small load stop mode or thesmall load stall mode, it can start timing as soon as controlling theengine (to start, remain the state unchanged, stall or stop), so as todetermine whether next start-stop control logic begins. In this way, thestate of the engine may be changed again after a predetermined periodsince the last state change, thus avoiding frequent start-stop of theengine.

Alternatively, a current operating mode of the hybrid electric vehicleand a discharge power of the power battery may also be obtained, and itmay be determined whether the hybrid electric vehicle is within thetaxiing start-stop interval according to the current gear position andthe current operating mode of the hybrid electric vehicle, the currentelectric charge level and the discharge power of the power battery, andthe slope of the road on which the hybrid electric vehicle is driving.

Specifically, data collectors in the BMS monitor the voltage and thecurrent of the power battery in real time, and then compute the electriccharge level and the discharge power of the power battery. When thevehicle is at a low temperature or when the vehicle has a fault, thepower battery has a risk of over discharge and over-low voltage. Thus,in order to protect the power battery from damage and prolong a use lifeof the power battery, the discharge power should be limited when thevehicle is at the low temperature or when the vehicle has a fault. Atthis time, the vehicle cannot output power normally.

A motor controller may determine a mode of the hybrid electric vehicleaccording to a mode switch signal, and then choose different drivingstrategies. Generally, the hybrid electric vehicle includes two workingmodes (electric mode and hybrid mode, EV and HEV) and two driving modes(Economy mode and Sport mode, ECO and Sport). Therefore, the hybridelectric vehicle may have four operating modes, such as EV-ECO mode,EV-Sport mode, HEV-ECO mode and HEV-Sport mode. In the EV mode, thevehicle is in a pure electric energy consumption mode and the motoroutputs power separately; in the HEV mode, the vehicle is in a hybridenergy consumption mode, and a ratio of power output by the motor topower output by the engine is determined according to a preset strategy.In the ECO mode, the power output from the motor and the engine islimited since the economy is a primary control target; in the Sportmode, the power output from the motor and the engine is not limitedsince the power performance is the primary control target, especially,in the hybrid economy mode (HEV-ECO mode), the engine remains running.

FIG. 2 is a flow chart of determining whether a hybrid electric vehicleis within a taxiing start-stop interval according to an embodiment ofthe present disclosure. As shown in FIG. 2, following steps areperformed.

In step S201, it is determined whether the current electric charge levelof the power battery is greater than a first electric charge threshold,and whether the discharge power of the power battery is greater than afirst power threshold, if the current gear position is at D-position,and the current operating mode is the hybrid economy mode (HEV-ECOmode).

The first electric charge threshold and the first power threshold may bedetermined according to a minimum electric charge level and a minimumdischarge power at which the power battery may supply power normally.When the electric charge level of the power battery is less than orequal to the first electric charge threshold or when the discharge powerof the power battery is less than or equal to the first power threshold,the power battery takes the risk of over discharging and low voltagealarm. Therefore, in order to protect the power battery from damage andensure the working life of the power battery, the first electric chargethreshold and the first power threshold should be set.

In step S202, if the current electric charge level of the power batteryis greater than the first electric charge threshold, and the dischargepower of the power battery is greater than the first power threshold, itis further determined whether the current electric charge level isgreater than or equal to a second electric charge threshold, and whethera difference between the current electric charge level and a targetstate of charge level of the power battery is less than a preset value.

The target state of charge level is an electric charge level which thepower battery finally has when charging or discharging under the HEVmode.

Therefore, if a difference between the current electric charge level andthe target state of charge level of the power battery is less than thepreset value, the current electric charge level of the power battery ishigher and has a smaller difference from the target state of chargelevel, and the power battery is in a balance state. In this case, thepower battery may not only meet a current driving requirement, but alsois in a stable discharge state, and thus may avoid the over dischargingeffectively when the hybrid electric vehicle enters a small load controlfunction, thereby protecting the power battery, prolonging the workinglife of the power battery, and remaining a better power performance andstability for the hybrid electric vehicle.

The small load control function refers to a drive control function usedwhen the electric charge level of the power battery is large enough(e.g. the electric charge level is larger than a second electric chargethreshold), the discharge power of the power battery is greater than thefirst power threshold, and the slope of the road satisfies a presetcondition.

If the slope of the road is ascent and the slope is less than a firstslope threshold, it is determined that the slope of the road meets thepreset condition.

If the slope of the road is descent and the slope is greater than orequal to a second slope threshold, it is also determined that the slopeof the road meets the preset condition.

The second electric charge threshold is an electric charge level whichmay satisfy the requirement of driving in a pure electric mode at a lowspeed, such that part of the electric charge level are reserved fordriving in a pure electric mode at a low speed when a taxiing start-stopcontrol is performed, thus remaining the better power performance andstability for the hybrid electric vehicle. The first electric chargethreshold and the second electric charge threshold may be set accordingto the driving habit of the user and the power consumption of the hybridelectric vehicle.

In step S203, if the current electric charge level is greater than orequal to the second electric charge threshold, and a difference betweenthe current electric charge level and the target state of charge levelof the power battery is less than the preset value, it is furtherdetermined whether the slope of the road meets a preset condition.

If the slope of the road is ascent and the slope is less than a firstslope threshold, it is determined that the slope of the road meets thepreset condition. If the slope of the road is descent and the slope isgreater than or equal to a second slope threshold, it is also determinedthat the slope of the road meets the preset condition.

In step S204, if the slope of the road meets the preset condition, it isdetermined that the hybrid electric vehicle is within the taxiingstart-stop interval.

In an embodiment of the present disclosure, after determining that thehybrid electric vehicle is within the taxiing start-stop interval, theengine start-stop control is performed according to the speed of thehybrid electric vehicle, as shown in FIG. 3 and relevant descriptions.

If the slope of the road is ascent and the slope is greater than orequal to the first slope threshold, the start-stop control on the engineis released, and the engine is controlled by the engine controller ofthe hybrid electric vehicle itself. If the slope of the road is descentand the slope is less than the second slope threshold, the engine isconfigured to stop, and the motor is configured to output powerseparately.

In another embodiment of the present disclosure, step S205 is furtherincluded.

In step S205, if the current electric charge level is less than thesecond electric charge threshold, or if the difference between thecurrent electric charge level and the target state of charge level ofthe power battery is greater than or equal to the preset value, it isdetermined that the hybrid electric vehicle is within a speed start-stopinterval.

In the taxiing start-stop interval, the engine is configured to start,stop or stall, while the accelerator pedal is released. In the speedstart-stop interval, the engine is configured to start, stop or stall,while the accelerator pedal is depressed. The control strategy for thetaxiing start-stop interval needs to consider factors like the speed,the working state of the engine, and the accelerator push depth, whilethe control strategy for the speed start-stop interval needs to considerfactors like the speed and the slope of the road. In other words, in thespeed start-stop interval, the engine is controlled according to thespeed and the slope of the road.

After determining that the hybrid electric vehicle is within the speedstart-stop interval, the speed start-stop control may be performedaccording to the slope of the road and the current speed. Specifically,if the slope of the road is ascent and the slope is greater than orequal to a third slope threshold, the engine is started; if the slope ofthe road is descent and the slope is greater than or equal to a fourthslope threshold, the engine is configured to stop, i.e., the fuel supplyfor the engine is cut off and the clutch is configured to be open (atthis time, the engine stops running), and the motor is configured tooutput power separately; if the slope of the road is ascent and lessthan the third slope threshold, and the current speed is greater than afirst speed threshold, the engine is started; if the slope of the roadis descent and less than the fourth slope threshold, and the currentspeed is greater than the first speed threshold, the engine is started.After starting the engine, the speed of the hybrid electric vehicle ismonitored in real time, and when the speed of the hybrid electricvehicle is less than a second speed threshold, the engine is configuredto stop, and the motor is configured to output power separately.

In the present disclosure, the first slope threshold, the second slopethreshold, the third slope threshold and the fourth slope threshold maybe set according to the driving habit of the user and the powerconsumption of the hybrid electric vehicle.

FIG. 4 is a schematic diagram of energy transfer in a drive controlprocess of the hybrid electric vehicle according to an embodiment of thepresent disclosure. As shown in FIG. 4, when the mode of the hybridelectric vehicle is the hybrid economy mode, the current electric chargelevel of the power battery (an electric charge level of a high-voltageiron battery) is greater than the second electric charge threshold, thedischarge power is less than or equal to the first power threshold, andthe slope of the road, the speed and the accelerator push depth meets alow-speed, small-throttle and low-power driving, the hybrid electricvehicle is driven by the motor separately, and the energy transfer isshown as route {circle around (1)} in FIG. 4. If the discharge power ofthe hybrid electric vehicle is greater than the second power threshold(i.e. requiring a large power driving), the engine is started to outputpower, and at this time, the power is transferred to wheels via a DCT(Dual Clutch Transmission) gearbox and a reducer, which is shown asroute {circle around (2)} in FIG. 4. Moreover, when the current electriccharge level of the hybrid electric vehicle reduces to a certainelectric charge level (less than or equal to the second electric chargethreshold), part of power of the engine is output to charge thehigh-voltage iron battery, the energy transfer of which is shown asroute {circle around (7)} in FIG. 4. In addition, when the braking pedalis depressed during the driving, or when the engine automatically stallsand stops running during idling, the motor transfers the kinetic energyof the whole vehicle to the electric energy for storing in the powerbattery, the energy transfer of which is shown as route {circle around(7)} in FIG. 4.

In embodiments of the present disclosure, the hybrid electric vehiclemay include the high-voltage iron battery used as the power battery anda low-voltage iron voltage used as the storage battery.

There are two ways for supplementing the electric charge level of thelow-voltage iron battery. The first one is driving the generator togenerate electricity when the engine start working, for charging thehigh-voltage iron battery, the energy transfer of which is shown asroute {circle around (5)} in FIG. 4, and the other one is transferring ahigh voltage in the high-voltage iron battery to a low voltage by aDC-DC converter, for charging the low-voltage iron battery, the energytransfer of which is shown as route {circle around (6)} in FIG. 4.

It can be seen that, in embodiments of the present disclosure, there aretwo ways for starting the engine. The first one is starting the enginedirectly by the starter, the energy transfer of which is shown as route{circle around (4)} in FIG. 4, and the other one is starting the enginevia inertia anti-drag force of the whole vehicle when the speed meets arequirement (i.e., the electric charge level of the power battery islarge enough, such that the speed reaches the requirement of inertiaanti-drag), the energy transfer of which is shown as route {circlearound (3)} in FIG. 4. Thus, if the speed reaches the certainrequirement, the starter does not need to work, such that a workingfrequency of the starter may not be increased, thus ensuring the workinglife of the components.

FIG. 5 is a schematic diagram of control information interaction in thedrive control process of the hybrid electric vehicle according to anembodiment of the present disclosure. As shown in FIG. 5, a speed signalis sent from an electronic stability controller (shown as ESC in FIG. 5)to a motor controller (shown as ECN in FIG. 5); a gear controller (shownas SCU in FIG. 5) is used to collect a gear signal and send the gearsignal to the ECN; a battery management system (shown as BMS is FIG. 5)is used to collect signals like current output power and currentelectric charge level and send collected signals to the ECN; the motorcontroller ECN is used to verify received signals like vehicle mode(such as EV/HEV/ECO/Sport mode) signal, accelerator signal or brakingpedal signal, send signals like a target torque of the engine, thevehicle mode, and start-stop identification of the engine to an enginecontrol module ECM, and send signals like the energy transfer state andthe vehicle mode to a combination instrument; the BMS performs thebattery monitoring and managing strategy; the ECM performs thestart-stop control strategy; and the combination instrument performs theenergy state and vehicle mode display strategy.

FIG. 6 is a flow chart of a drive control method of a hybrid electricvehicle according to an example embodiment of the present disclosure. Asshown in FIG. 6, the drive control method of the hybrid electric vehicleincludes following steps.

In step S601, it is determined whether the gear of the hybrid electricvehicle is at a preset position, if yes, step S602 is performed, and ifno, step S605 is performed.

The preset position may be D gear position.

In step S602, it is determined whether the hybrid electric vehicle is ina preset operating mode, if yes, step S603 is performed, and if no, stepS605 is performed.

The preset operating mode may be the hybrid economy mode.

In step S603, it is determined whether the current electric charge levelof the power battery is greater than the first electric chargethreshold, and whether the discharge power of the power battery isgreater than the first power threshold are determined, if yes, step S604is performed, and if no, step S605 is performed.

In step S604, it is determined whether the current electric charge levelof the hybrid electric vehicle is greater than or equal to the secondelectric charge threshold, and whether the difference between thecurrent electric charge level and a target state of charge level of thepower battery is less than a preset value, if yes, step S607 isperformed, and if no, step S606 is performed.

In step S605, the hybrid electric vehicle quits from the enginestart-stop control.

In step S606, the hybrid electric vehicle enters the speed start-stopcontrol.

Specifically, if the slope of the road is ascent and the slope isgreater than or equal to a third slope threshold (p3), the engine isstarted, and the engine is configured to output power for the vehicle;if the slope of the road is descent and the slope is greater than orequal to a fourth slope threshold (p4), the engine is configured tostop, and the motor is configured to output power separately; if theslope of the road is ascent and less than the third slope threshold(p3), and the current speed is greater than a first speed threshold, theengine is started; if the slope of the road is descent and less than thefourth slope threshold (p4), and the current speed is greater than thefirst speed threshold, the engine is started. After starting the engine,it may be further determined whether the speed of the hybrid electricvehicle is less than a second speed threshold, if yes, the engine isconfigured to stop and the motor is configured to output powerseparately, and if no, step S601 is returned to, for performing theengine start-stop control procedure again.

In step S607, the slope of the road on which the hybrid electric vehicleis driving is obtained.

In step S608, it is determined whether the slope of the road is ascentand the slope is less than a first slope threshold (p1), if yes, stepS610 is performed, and if no, step S605 is performed.

In step S609, it is determined whether the slope of the road is descentand the slope is less than a second slope threshold (p2), if yes, stepS611 is performed, and if no, step S610 is performed.

In step S610, the current speed of the hybrid electric vehicle isobtained.

In step S611, the engine is configured to stop, and the motor isconfigured to output power separately.

In step S612, if the current speed is less than a third speed threshold,the engine is configured to stop, and the motor is configured to outputpower separately.

In step S613, if the current speed is greater than or equal to a thirdspeed threshold, and less than a fourth speed threshold, the hybridelectric vehicle is configured to enter the small load stop mode.

Specifically, it is first determined whether the engine is in anoperating state. If the engine is not in the operating state, it isfurther determined whether an accelerator push depth (d) is greater thanor equal to a first accelerator threshold (n). If the accelerator pushdepth is greater than or equal to the first accelerator threshold (n),the engine is started; and if the accelerator push depth is less thanthe first accelerator threshold (n), the state of the engine remainsunchanged.

If the engine is in the operating state, it is further determinedwhether the accelerator push depth is less than a second acceleratorthreshold (m). If the accelerator push depth is less than the secondaccelerator threshold (m), the engine is configured to stop; and if theaccelerator push depth is greater than or equal to the secondaccelerator threshold (m), the state of the engine remains unchanged.

The first accelerator threshold and the second accelerator threshold maybe set according to a driving habit of a user and a performance of thehybrid electric vehicle.

In step S614, if the current speed is greater than or equal to thefourth speed threshold, and less than a fifth speed threshold, thehybrid electric vehicle is configured to enter the small load stallmode.

Specifically, it is first determined whether the engine is in anoperating state. If the engine is not in the operating state, it isfurther determined whether the accelerator push depth (d) is greaterthan or equal to the first accelerator threshold (n). If the acceleratorpush depth is greater than or equal to the first accelerator threshold(n), the engine is started; and if the accelerator push depth is lessthan the first accelerator threshold (n), the state of the engineremains unchanged.

If the engine is in the operating state, it is further determinedwhether the accelerator push depth is less than the second acceleratorthreshold (m). If the accelerator push depth is less than the secondaccelerator threshold (m), the engine is configured to stall, the clutchis remained in a coupling state, and fuel supply for the engine is cutoff; and if the accelerator push depth is greater than or equal to thesecond accelerator threshold (m), the state of the engine remainsunchanged.

The first accelerator threshold and the second accelerator threshold maybe set according to the driving habit of the user and the performance ofthe hybrid electric vehicle. The second accelerator threshold is lessthan the first accelerator, thus avoiding a frequent engine start andstop caused by unclear accelerator thresholds.

In step S615, if the current speed is greater than the fifth speedthreshold, the state of the engine remains unchanged.

In the above-described process, when controlling the engine, the motoris in the operating state, such that the motor may provide power for thevehicle separately or provide power for the vehicle along with theengine, according to different working states of the engine.

With the drive control method of the hybrid electric vehicle accordingto embodiments of the present disclosure, whether the hybrid electricvehicle is within the taxiing start-stop interval is determinedaccording to information such as the current gear position of the hybridelectric vehicle and the current electric charge level of the powerbattery, and if the hybrid electric vehicle is within the taxiingstart-stop interval, the hybrid electric vehicle is configured to entera small load stop mode or a small load stall mode according to thecurrent speed. In this way, a driving distance for the vehicle may beincreased, an economy performance may be improved, and fuel consumptionand emission may be reduced, without increasing a working frequency ofthe starter, thus ensuring a working life of components. In addition, ifthe vehicle has an accelerator-releasing energy feedback function,wasted kinetic energy may be converted to electric energy by a motorthrough the energy feedback and stored in a power battery, thusincreasing energy recovery. Moreover, for the hybrid electric vehicles,problems of bad ride comfort and bad power performance caused byfrequent start-stop of the engine may be solved effectively.

In order to realize above embodiments, a drive control device of ahybrid electric vehicle is also provided in the present disclosure.

FIG. 7 is a block diagram of a drive control device of a hybrid electricvehicle according to an embodiment of the present disclosure.

As shown in FIG. 7, the drive control device according to an embodimentof the present disclosure includes a first obtaining module 10, adetermining module 20, a second obtaining module 30 and a first controlmodule 40.

Specifically, the first obtaining module 10 is configured to obtain acurrent gear position of the hybrid electric vehicle, a current electriccharge level of a power battery and a slope of a road on which thehybrid electric vehicle is driving.

The determining module 20 is configured to determine whether the hybridelectric vehicle is within a taxiing start-stop interval according tothe current gear position of the hybrid vehicle, the current electriccharge level of the power battery, and the slope of the road.

The second obtaining module 30 is configured to obtain a current speedof the hybrid electric vehicle, if the hybrid electric vehicle is withinthe taxiing start-stop interval.

The first control module 40 is configured to cause the hybrid electricvehicle to enter a small load stop mode or a small load stall modeaccording to the current speed, for example, execute steps shown in FIG.3.

FIG. 8 is a block diagram of a drive control device of a hybrid electricvehicle according to another embodiment of the present disclosure. Asshown in FIG. 8, based on the embodiment shown in FIG. 7, the drivecontrol device in the embodiment shown in FIG. 8 further includes athird obtaining module 50.

The third obtaining module 50 is configured to obtain a currentoperating mode of the hybrid electric vehicle and a discharge power ofthe power battery. Moreover, the determining module 20 is configured todetermine whether the hybrid electric vehicle is within the taxiingstart-stop interval according to the current gear position and thecurrent operating mode of the hybrid electric vehicle, the currentelectric charge level and the discharge power of the power battery, andthe slope of the road.

Specifically, the determining module 20 may include a first determiningunit 21, a second determining unit 22, a third determining unit 23 and afourth determining unit 24.

The first determining unit 21 is configured to determine whether thecurrent electric charge level of the power battery is greater than afirst electric charge threshold, and whether the discharge power of thepower battery is greater than a first power threshold, if the currentgear position is at D-position and the current operating mode is ahybrid economy mode.

The second determining unit 22 is configured to determine whether thecurrent electric charge level is greater than or equal to a secondelectric charge threshold, and whether a difference between the currentelectric charge level and the target state of charge level of the powerbattery is less than a preset value, if the current electric chargelevel of the power battery is greater than the first electric chargethreshold, and the discharge power of the power battery is greater thanthe first power threshold.

The third determining unit 23 is configured to determine whether theslope of the road meets a preset condition, if the current electriccharge level is greater than or equal to the second electric chargethreshold, and the difference between the current electric charge leveland a target state of charge level of the power battery is less than thepreset value. If the slope of the road is ascent and the slope is lessthan a first slope threshold, the slope of the road meets the presetcondition. If the slope of the road is descent and the slope is greaterthan or equal to a second slope threshold, the slope of the road alsomeets the preset condition.

The fourth determining unit 24 is configured to determine that thehybrid electric vehicle is within the taxiing start-stop interval, ifthe slope of the road meets the present condition.

In an embodiment of the present disclosure, after the fourth determiningunit 24 determines that the slope of the road meets the presetcondition, the engine start-stop strategy may be performed as describedin the above method embodiments. If the slope of the road does not meetthe preset condition, the first control module 40 is further configuredto: release the start-stop control on an engine, if the slope of theroad is ascent and the slope is greater than or equal to the first slopethreshold (at this time, the engine is controlled by the enginecontroller in the hybrid electric vehicle itself); and stop the engine,and cause a motor to output power separately, if the slope of the roadis descent and the slope is less than the second slope threshold.

Alternatively, the determining module 20 may further include a fifthdetermining unit 25, configured to determine that the hybrid electricvehicle is within a speed start-stop interval, if the current electriccharge level is less than the second electric charge threshold, or ifthe difference between the current electric charge level and the targetstate of charge level of the power battery is greater than or equal tothe preset value.

FIG. 9 is a block diagram of a drive control device of a hybrid electricvehicle according to yet another embodiment of the present disclosure.As shown in FIG. 9, based on the above embodiments, the drive controldevice further includes a second control module 60.

After it is determined that the hybrid electric vehicle is within thespeed start-stop interval, the second control module 60 is configuredto: start the engine, if the slope of the actual road is ascent and theslope is greater than or equal to a third slope threshold; stop theengine, and cause a motor to output power separately, if the slope ofthe actual road is descent and the slope is greater than or equal to afourth slope threshold; start the engine, if the slope of the road isascent and less than the third slope threshold, and the current speed isgreater than a first speed threshold; start the engine, if the slope ofthe road is descent, and less than the fourth slope threshold, and thecurrent speed is greater than the first speed threshold; obtain a speedof the hybrid electric vehicle after starting the engine; stop theengine, and cause the motor to output power separately, if the speed ofthe hybrid electric vehicle is less than a second speed threshold.

With respect to the devices in the above embodiments, the specificoperation modes of individual modules therein have been described indetail in the embodiments regarding the drive control method of thehybrid electric vehicle, which will not be elaborated herein.

With the drive control device of the hybrid electric vehicle accordingto embodiments of the present disclosure, whether the hybrid electricvehicle is within the taxiing start-stop interval is determinedaccording to information such as the current gear position of the hybridelectric vehicle and the current electric charge level of the powerbattery, and if the hybrid electric vehicle is within the taxiingstart-stop interval, the hybrid electric vehicle is configured to entera small load stop mode or a small load stall mode according to thecurrent speed. In this way, a driving distance for the vehicle may beincreased, an economy performance may be improved, and fuel consumptionand emission may be reduced, without increasing a working frequency ofthe starter, thus ensuring a working life of components. In addition, ifthe vehicle has an accelerator-releasing energy feedback function,wasted kinetic energy may be converted to electric energy by a motorthrough the energy feedback and stored in a power battery, thusincreasing energy recovery. Moreover, for the hybrid electric vehicles,problems of bad ride comfort and bad power performance caused byfrequent start-stop of the engine may be solved effectively.

In order to realize the above embodiments, a hybrid electric vehicle isalso provided in the present disclosure. The hybrid electric vehicleincludes the drive control device described in any of above embodiments.

With the hybrid electric vehicle according to embodiments of the presentdisclosure, whether the hybrid electric vehicle is within the taxiingstart-stop interval is determined according to information such as thecurrent gear position of the hybrid electric vehicle and the currentelectric charge level of the power battery, and if the hybrid electricvehicle is within the taxiing start-stop interval, the hybrid electricvehicle is configured to enter a small load stop mode or a small loadstall mode according to the current speed. In this way, a drivingdistance for the vehicle may be increased, an economy performance may beimproved, and fuel consumption and emission may be reduced, withoutincreasing a working frequency of the starter, thus ensuring a workinglife of components. In addition, if the vehicle has anaccelerator-releasing energy feedback function, wasted kinetic energymay be converted to electric energy by a motor through the energyfeedback and stored in a power battery, thus increasing energy recovery.Moreover, for the hybrid electric vehicles, problems of bad ride comfortand bad power performance caused by frequent start-stop of the enginemay be solved effectively.

In the specification, it is to be understood that terms such as“central,” “longitudinal,” “lateral,” “length,” “width,” “thickness,”“upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,”“horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and“counterclockwise” should be construed to refer to the orientation asthen described or as shown in the drawings under discussion. Theserelative terms are for convenience of description and do not requirethat the present invention be constructed or operated in a particularorientation.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance or to imply the number of indicatedtechnical features. Thus, the feature defined with “first” and “second”may comprise one or more of this feature. In the description of thepresent invention, “a plurality of” means two or more than two, unlessspecified otherwise.

In the present disclosure, unless specified or limited otherwise, theterms “mounted,” “connected,” “coupled,” “fixed” and the like are usedbroadly, and may be, for example, fixed connections, detachableconnections, or integral connections; may also be mechanical orelectrical connections; may also be direct connections or indirectconnections via intervening structures; may also be inner communicationsof two elements, which can be understood by those skilled in the artaccording to specific situations.

In the present disclosure, unless specified or limited otherwise, astructure in which a first feature is “on” or “below” a second featuremay include an embodiment in which the first feature is in directcontact with the second feature, and may also include an embodiment inwhich the first feature and the second feature are not in direct contactwith each other, but are contacted via an additional feature formedtherebetween. Furthermore, a first feature “on,” “above,” or “on top of”a second feature may include an embodiment in which the first feature isright or obliquely “on,” “above,” or “on top of” the second feature, orjust means that the first feature is at a height higher than that of thesecond feature; while a first feature “below,” “under,” or “on bottomof” a second feature may include an embodiment in which the firstfeature is right or obliquely “below,” “under,” or “on bottom of” thesecond feature, or just means that the first feature is at a heightlower than that of the second feature.

Reference throughout this specification to “an embodiment,” “someembodiments,” “one embodiment”, “another example,” “an example,” “aspecific example,” or “some examples,” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, the appearances of the phrases such as“in some embodiments,” “in one embodiment”, “in an embodiment”, “inanother example,” “in an example,” “in a specific example,” or “in someexamples,” in various places throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

Although explanatory embodiments have been shown and described, it wouldbe appreciated by those skilled in the art that the above embodimentscannot be construed to limit the present disclosure, and changes,alternatives, and modifications can be made in the embodiments withoutdeparting from spirit, principles and scope of the present disclosure.

What is claimed is:
 1. A drive control method of a hybrid electricvehicle, comprising: obtaining a current gear position of the hybridelectric vehicle, a current electric charge level of a power battery anda slope of a road on which the hybrid electric vehicle is driving;determining whether the hybrid electric vehicle is within a taxiingstart-stop interval according to the current gear position of the hybridvehicle, the current electric charge level of the power battery, and theslope of the road on which the hybrid electric vehicle is driving; ifthe hybrid electric vehicle is within the taxiing start-stop interval,obtaining a current speed of the hybrid electric vehicle; and causingthe hybrid electric vehicle to enter a small load stop mode or a smallload stall mode according to the current speed.
 2. The drive controlmethod according to claim 1, further comprising: obtaining a currentoperating mode of the hybrid electric vehicle and a discharge power ofthe power battery; and determining whether the hybrid electric vehicleis within the taxiing start-stop interval according to the current gearposition and the current operating mode of the hybrid electric vehicle,the current electric charge level and the discharge power of the powerbattery, and the slope of the road on which the hybrid electric vehicleis driving.
 3. The drive control method according to claim 2, whereindetermining whether the hybrid electric vehicle is within the taxiingstart-stop interval according to the current gear position and thecurrent operating mode of the hybrid electric vehicle, the currentelectric charge level and the discharge power of the power battery, andthe slope of the road on which the hybrid electric vehicle is drivingcomprises: determining whether the current gear position is atD-position and whether the current operating mode is a hybrid economymode; if the current gear position is at D-position and the currentoperating mode is the hybrid economy mode, further determining whetherthe current electric charge level of the power battery is greater than afirst electric charge threshold, and whether the discharge power of thepower battery is greater than a first power threshold; if the currentelectric charge level of the power battery is greater than the firstelectric charge threshold, and the discharge power of the power batteryis greater than the first power threshold, further determining whetherthe current electric charge level is greater than or equal to a secondelectric charge threshold, and whether a difference between the currentelectric charge level and a target state of charge level of the powerbattery is less than a preset value; if the current electric chargelevel is greater than or equal to the second electric charge threshold,and the difference between the current electric charge level and thetarget state of charge level of the power battery is less than thepreset value, further determining whether the slope of the road meets apreset condition; and if the slope of the road meets the presetcondition, determining that the hybrid electric vehicle is within thetaxiing start-stop interval.
 4. The drive control method according toclaim 3, wherein if the slope of the road is ascent and the slope isless than a first slope threshold, it is determined that the slope ofthe road meets the preset condition; and if the slope of the road isdescent and the slope is greater than or equal to a second slopethreshold, it is determined that the slope of the road meets the presetcondition.
 5. The drive control method according to claim 4, wherein ifthe slope of the road is ascent and the slope is greater than or equalto the first slope threshold, an engine is released from a start-stopcontrol; and if the slope of the road is descent and the slope is lessthan the second slope threshold, the engine is configured to stop, and amotor is configured to output power separately.
 6. The drive controlmethod according to claim 3, further comprising: determining that thehybrid electric vehicle is within a speed start-stop interval, if thecurrent electric charge level is less than the second electric chargethreshold, or if the difference between the current electric chargelevel and the target state of charge level of the power battery isgreater than or equal to the preset value.
 7. The drive control methodaccording to claim 6, further comprising: after determining that thehybrid electric vehicle is within the speed start-stop interval:starting an engine, if the slope of the road is ascent and the slope isgreater than or equal to a third slope threshold; stopping the engineand causing a motor to output power separately, if the slope of the roadis descent and the slope is greater than or equal to a fourth slopethreshold; starting the engine, if the slope of the road is ascent andthe slope is less than the third slope threshold, and the current speedis greater than a first speed threshold, or if the slope of the road isdescent and the slope is less than the fourth slope threshold, and thecurrent speed is greater than the first speed threshold; obtaining aspeed of the hybrid electric vehicle after starting the engine; andstopping the engine and causing the motor to output power separately, ifthe speed of the hybrid electric vehicle is less than a second speedthreshold.
 8. The drive control method according to claim 1, whereincausing the hybrid electric vehicle to enter a small load stop mode or asmall load stall mode according to the current speed comprises: if thecurrent speed is less than a third speed threshold, stopping an engine,and causing a motor to output power separately; if the current speed isgreater than or equal to a third speed threshold, and less than a fourthspeed threshold, causing the hybrid electric vehicle to enter the smallload stop mode; if the current speed is greater than or equal to thefourth speed threshold, and less than a fifth speed threshold, causingthe hybrid electric vehicle to enter the small load stall mode; and ifthe current speed is greater than the fifth speed threshold, maintainingthe engine at its current state.
 9. The drive control method accordingto claim 8, wherein causing the hybrid electric vehicle to enter thesmall load stop mode comprises: if the engine is not in an operatingstate: starting the engine, if an accelerator push depth is greater thanor equal to a first accelerator threshold; maintain the engine at itscurrent state, if the accelerator push depth is less than the firstaccelerator threshold; if the engine is in the operating state: stoppingthe engine, if the accelerator push depth is less than a secondaccelerator threshold, in which the second accelerator threshold is lessthan the first accelerator threshold; and maintain the engine at itscurrent state, if the accelerator push depth is greater than or equal tothe second accelerator threshold.
 10. The drive control method accordingto claim 8, wherein causing the hybrid electric vehicle to enter thesmall load stall mode comprises: if the engine is not in the operatingstate: starting the engine, if an accelerator push depth is greater thanor equal to a first accelerator threshold; maintain the engine at itscurrent state, if the accelerator push depth is less than the firstaccelerator threshold; if the engine is in the operating state: stallingthe engine, keeping a clutch in a coupling state, and terminating fuelsupply to the engine, if the accelerator push depth is less than asecond accelerator threshold, in which the second accelerator thresholdis less than the first accelerator threshold; and maintain the engine atits current state, if the accelerator push depth is greater than orequal to the second accelerator threshold.
 11. A drive control device ofa hybrid electric vehicle, comprising: a first obtaining module,configured to obtain a current gear position of the hybrid electricvehicle, a current electric charge level of a power battery and a slopeof a road on which the hybrid electric vehicle is driving; a determiningmodule, configured to determine whether the hybrid electric vehicle iswithin a taxiing start-stop interval according to the current gearposition of the hybrid electric vehicle, the current electric chargelevel of the power battery, and the slope of the road on which thehybrid electric vehicle is driving; a second obtaining module,configured to obtain a current speed of the hybrid electric vehicle, ifthe hybrid electric vehicle is within the taxiing start-stop interval;and a first control module, configured to cause the hybrid electricvehicle to enter a small load stop mode or a small load stall modeaccording to the current speed.
 12. The drive control device accordingto claim 11, further comprising: a third obtaining module, configured toobtain a current operating mode of the hybrid electric vehicle and adischarge power of the power battery, wherein, the determining module isconfigured to determine whether the hybrid electric vehicle is withinthe taxiing start-stop interval according to the current gear positionand the current operating mode of the hybrid electric vehicle, thecurrent electric charge level and the discharge power of the powerbattery, and the slope of the road on which the hybrid electric vehicleis driving.
 13. The drive control device according to claim 12, whereinthe determining module comprises: a first determining unit, configuredto determine whether the current electric charge level of the powerbattery is greater than a first electric charge threshold, and whetherthe discharge power of the power battery is greater than a first powerthreshold, if the current gear position is at D-position and the currentoperating mode is a hybrid economy mode; a second determining unit,configured to determine whether the current electric charge level isgreater than or equal to a second electric charge threshold, and whethera difference between the current electric charge level and a targetstate of charge level of the power battery is less than a preset value,if the current electric charge level of the power battery is greaterthan the first electric charge threshold, and the discharge power of thepower battery is greater than the first power threshold; a thirddetermining unit, configured to determine whether the slope of the roadmeets a preset condition, if the current electric charge level isgreater than or equal to the second electric charge threshold, and thedifference between the current electric charge level and the targetstate of charge level of the power battery is less than the presetvalue; and a fourth determining unit, configured to determine that thehybrid electric vehicle is within the taxiing start-stop interval, ifthe slope of the road meets the present condition.
 14. The drive controldevice according to claim 13, wherein the third determining unit isconfigured to: determine that the slope of the road meets the presetcondition, if the slope of the road is ascent and the slope is less thana first slope threshold; and determine that the slope of the road meetsthe preset condition, if the slope of the road is descent and the slopeis greater than or equal to a second slope threshold.
 15. The drivecontrol device according to claim 14, wherein, the first control moduleis further configured to: release an engine from a start-stop control,if the slope of the actual road is ascent and the slope is greater thanor equal to the first slope threshold; and stop the engine, and controla motor to output power separately, if the slope of the road is descentand the slope is less than the second slope threshold.
 16. The drivecontrol device according to claim 13, wherein, the determining modulefurther comprises: a fifth determining unit, configured to determinethat the hybrid electric vehicle is within a speed start-stop interval,if the current electric charge level is less than the second electriccharge threshold, or if the difference between the current electriccharge level and the target state of charge level of the power batteryis less than the preset value.
 17. The drive control device according toclaim 16, further comprising a second control module, wherein the secondcontrol module is configured to: start the engine, if the slope of theroad is ascent and the slope is greater than or equal to a third slopethreshold; stop the engine, and cause a motor to output powerseparately, if the slope of the road is descent and the slope is greaterthan or equal to a fourth slope threshold; start the engine, if theslope of the road is ascent and less than the third slope threshold, andthe current speed is greater than a first speed threshold, or if theslope of the road is descent and less than the fourth slope threshold,and the current speed is greater than the first speed threshold; obtaina speed of the hybrid electric vehicle after starting the engine; andstop the engine and cause the motor to output power separately, if thespeed of the hybrid electric vehicle is less than a second speedthreshold.
 18. The drive control device according to claim 11, wherein,the first control module is configured to: stop the engine, and cause amotor to output power separately, if the current speed is less than athird speed threshold; cause the hybrid electric vehicle to enter thesmall load stop mode, if the current speed is greater than or equal to athird speed threshold, and less than a fourth speed threshold; cause thehybrid electric vehicle to enter the small load stall mode, if thecurrent speed is greater than or equal to the fourth speed threshold,and less than a fifth speed threshold; and maintain the engine at itscurrent state, if the current speed is greater than the fifth speedthreshold.
 19. The drive control device according to claim 18, wherein,the first control module is configured to: if the engine is not in anoperating state: start the engine, if an accelerator push depth isgreater than or equal to a first accelerator threshold; maintain theengine at its current state, if the accelerator push depth is less thanthe first accelerator threshold; if the engine is in the operatingstate: stop the engine, if the accelerator push depth is less than asecond accelerator threshold, in which the second accelerator thresholdis less than the first accelerator threshold; maintain the engine at itscurrent state, if the accelerator push depth is greater than or equal tothe second accelerator threshold.
 20. A hybrid electric vehicle,comprising the drive control device according to claim 11.